Light-emitting device and method of manufacturing the same

ABSTRACT

A light-emitting device may comprise a substrate, an electric wire fixed to the substrate, and a plurality of light-emitting diodes mounted to the electric wire. According to one embodiment, each of the plurality of light-emitting diodes is an LED chip, and the light-emitting diodes on the substrate are sealed individually or collectively by one or more sealing members. According to another embodiment, the substrate has a plurality of through holes, wherein a plurality of portions of the electric wire provided on a rear surface side of the substrate communicates with a front surface side of the substrate at the plurality of through holes of the substrate, and wherein the plurality of light-emitting diodes is respectively mounted to the respective portions of the electric wire that communicate with the front surface side of the substrate. Other embodiments relate to methods of manufacturing a light-emitting device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to and the benefit of Japanese PatentApplication No. 2013-132161, filed on Jun. 25, 2013; Japanese PatentApplication No. 2012-206898, filed on Sep. 20, 2012; and Japanese PatentApplication No. 2012-192454, filed on Aug. 31, 2012, each of which ishereby incorporated by reference in their entireties.

BACKGROUND

1. Technical Field

The present disclosure relates to a light-emitting device and a methodof manufacturing the light-emitting device.

2. Discussion of Related Art

Recently, light-emitting devices using light-emitting diodes such as LEDlighting (for example, refer to “Description of Lighting Fixture Mountedwith a Straight-Tube LED Lamp”, [online], Feb. 28, 2010, PanasonicCorporation, [retrieved Aug. 5, 2012], Internet <URL:http://www.hkd.meti.go.jp/hokne/h22enematch/2data05.pdf>) are becomingwidely popular.

However, since light-emitting devices using light-emitting diodes arestill very expensive compared to conventional light-emitting devicessuch as an incandescent bulb or a fluorescent lamp, a further reductionin prices must be achieved in order to promote popularization of suchlight-emitting devices.

SUMMARY

In one embodiment of the present invention, a light-emitting device maycomprise at least one substrate, at least one electric wire fixed to thesubstrate, and a plurality of light-emitting diodes mounted to theelectric wire. Each of the plurality of light-emitting diodes is an LEDchip. The light-emitting diodes on the substrate are sealed individuallyor collectively by one or more sealing members.

According to another embodiment of the present invention, alight-emitting device may comprise: at least one substrate having aplurality of through holes; at least one electric wire provided on arear surface side of the substrate; and a plurality of light-emittingdiodes. A plurality of portions of the electric wire provided on therear surface side of the substrate communicates with a front surfaceside of the substrate at the plurality of through holes of thesubstrate. The plurality of light-emitting diodes is respectivelymounted to the respective portions of the electric wire that communicatewith the front surface side of the substrate.

According to another embodiment of the present invention, a method ofmanufacturing a light-emitting device, may comprise the steps of:preparing at least one substrate having a plurality of through holes;providing an electric wire on a rear surface side of the substrate sothat a plurality of portions of the electric wire communicates with afront surface side of the substrate at the plurality of through holes ofthe substrate; and respectively mounting a plurality of light-emittingdiodes to the respective portions of the electric wire that communicatewith the front surface side of the substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1C are schematic configuration diagrams of a light-emittingdevice according to a first embodiment, in which FIG. 1A is aperspective view, FIG. 1B is a partially enlarged view which shows anenlargement of a portion denoted by A in FIG. 1A, and FIG. 1C is adiagram partially showing a cross section taken along B-B in FIG. 1B.

FIGS. 2A-2C are schematic configuration diagrams of a light-emittingdevice according to a second embodiment, in which FIG. 2A is aperspective view, FIG. 2B is a partially enlarged view which shows anenlargement of a portion denoted by A in FIG. 2A, and FIG. 2C is adiagram showing a cross section taken along B-B in FIG. 2B.

FIGS. 3A-3C are schematic configuration diagrams of a light-emittingdevice according to a third embodiment, in which FIG. 3A is aperspective view, FIG. 3B is a partially enlarged view which shows anenlargement of a portion denoted by A in FIG. 3A, and FIG. 3C is adiagram showing a cross section taken along B-B in FIG. 3B.

FIG. 4 is a schematic plan diagram of a light-emitting device accordingto a fourth embodiment.

FIG. 5 is a schematic plan diagram of a light-emitting device accordingto a fifth embodiment.

FIGS. 6A-6C are diagrams showing a schematic configuration of alight-emitting device according to a sixth embodiment, in which FIG. 6Ais a perspective view, FIG. 6B is a partially enlarged view which showsan enlargement of a portion denoted by A in FIG. 6A, and FIG. 6C is adiagram showing a cross section taken along B-B in FIG. 6B.

FIGS. 7A-7C are diagrams showing a schematic configuration of alight-emitting device according to a seventh embodiment, in which FIG.7A is a perspective view, FIG. 7B is a partially enlarged view whichshows an enlargement of a portion denoted by A in FIG. 7A, and FIG. 7Cis a diagram showing a cross section taken along B-B in FIG. 7B.

FIGS. 8A-8C are diagrams showing a schematic configuration of alight-emitting device according to an eighth embodiment.

FIG. 9 is a schematic plan view showing an example (Example 1) of amethod of forming electrodes on one or more electric wire 8.

FIG. 10 is a schematic plan view showing an example (Example 2) of amethod of forming electrodes on one or more electric wire 8.

FIGS. 11A-11C are diagrams showing an example (Example 3) of a method offorming electrodes on one or more electric wire 8.

FIG. 12 is a diagram showing an example (Example 4) of a method offorming an electrode on one or more electric wire 8.

FIGS. 13A-13E are partially enlarged views of a light-emitting deviceshowing a method of manufacturing a light-emitting device according to asixth example.

FIGS. 14A-14E are partially enlarged views of a light-emitting deviceshowing a method of manufacturing a light-emitting device according to aseventh example.

FIGS. 15A-15D are partially enlarged views of a light-emitting deviceshowing a method of manufacturing a light-emitting device according toan eighth example.

DETAILED DESCRIPTION

Hereinafter, embodiments will be described with reference to theaccompanying drawings.

[Light-Emitting Device According to a First Embodiment]

FIGS. 1A-1C are schematic configuration diagrams of a light-emittingdevice according to a first embodiment, in which FIG. 1A is aperspective view, FIG. 1B is a partially enlarged view which shows anenlargement of a portion denoted by A in FIG. 1A, and FIG. 1C is adiagram partially showing a cross section taken along B-B in FIG. 1B.

As shown in FIGS. 1A-1C, the light-emitting device according to thefirst embodiment comprises a substrate 4, a plurality of electric wires8 fixed at predetermined intervals to the substrate 4 using adhesives12, and a plurality of light-emitting diodes 10 mounted to the electricwires 8 so that the plurality of electric wires 8 form a single line.With the light-emitting device according to the first embodiment, alight-emitting device in which the plurality of light-emitting diodes 10are connected in series can be inexpensively provided by a simpleconfiguration using the substrate 4 and the electric wires 8. Fixingusing the adhesive 12 is an example of means for fixing the electricwire 8.

[Light-Emitting Device According to a Second Embodiment]

FIGS. 2A-2C are schematic configuration diagrams of a light-emittingdevice according to a second embodiment, in which FIG. 2A is aperspective view, FIG. 2B is a partially enlarged view which shows anenlargement of a portion denoted by A in FIG. 2A, and FIG. 2C is adiagram showing a cross section taken along B-B in FIG. 2B.

As shown in FIGS. 2A-2C, the light-emitting device according to thesecond embodiment comprises a substrate 4, two electric wires 8 fixed tothe substrate 4 using adhesives 12, and a plurality of light-emittingdiodes 10 mounted to the electric wires 8 so that respective positiveand negative electrodes of the light-emitting diodes 10 are joined tothe two electric wires 8. With the light-emitting device according tothe second embodiment, a light-emitting device in which the plurality oflight-emitting diodes 10 are connected in parallel can be inexpensivelyprovided by a simple configuration using the substrate 4 and theelectric wires 8. Fixing using the adhesive 12 is an example of meansfor fixing the electric wire 8.

[Light-Emitting Device According to a Third Embodiment]

FIGS. 3A-3C are diagrams showing a schematic configuration of alight-emitting device according to a third embodiment, in which FIG. 3Ais a perspective view, FIG. 3B is a partially enlarged view which showsan enlargement of a portion denoted by A in FIG. 3A, and FIG. 3C is adiagram showing a cross section taken along B-B in FIG. 3B.

As shown in FIGS. 3A-3C, the light-emitting device according to thethird embodiment comprises a substrate 4, a single electric wire 8 fixedto the substrate 4 by winding, and a plurality of light-emitting diodes10 mounted to the single electric wire 8. With the light-emitting deviceaccording to the third embodiment, a light-emitting device in which theplurality of light-emitting diodes 10 are connected in series can beinexpensively provided by a simple configuration using the substrate 4and the electric wire 8. Fixing by winding is an example of means forfixing the electric wire 8. The electric wire 8 can be bonded to thesubstrate 4 (Specifically, an insulating layer 6) using adhesives 12after being fixed to the substrate 4 by winding.

[Light-Emitting Device According to a Fourth Embodiment]

FIG. 4 is a schematic plan view of a light-emitting device according toa fourth embodiment.

As shown in FIG. 4, the light-emitting device according to the fourthembodiment comprises two substrates 4 (since insulating layers 6 (to bedescribed later) are provided on surfaces of the substrates 4, thesubstrates 4 do not appear in FIG. 4), a plurality of electric wires 8fixed to the substrates 4 using fixing tapes, short-circuit electricwires 22 which short-circuit the plurality of electric wires 8 so that aseries-parallel circuit is formed, and a plurality of light-emittingdiodes 10 mounted to the plurality of electric wires 8. With thelight-emitting device according to the fourth embodiment, alight-emitting device in which the plurality of light-emitting diodes 10are connected in series-parallel can be inexpensively provided by asimple configuration using the substrates 4 and the electric wires 8.Fixing using the tape is an example of means for fixing the electricwire 8.

[Light-Emitting Device According to a Fifth Embodiment]

FIG. 5 is a schematic plan view of a light-emitting device according toa fifth embodiment.

As shown in FIG. 5, the light-emitting device according to the fifthembodiment comprises a substrate 4 (since an insulating layer 6 (to bedescribed later) is provided on a surface of the substrate 4, thesubstrate 4 does not appear in FIG. 5), a plurality of electric wires 8fixed to the substrate 4 using adhesives, short-circuit electric wires22 which short-circuit the plurality of electric wires 8 so that aparallel-series circuit is formed, and a plurality of light-emittingdiodes 10 mounted to the plurality of electric wires 8. With thelight-emitting device according to the fifth embodiment, alight-emitting device in which the plurality of light-emitting diodes 10are connected in parallel-series can be inexpensively provided by asimple configuration using the substrate 4 and the electric wires 8.Fixing using the adhesive is an example of means for fixing the electricwire 8.

With the light-emitting devices according to the first to fifthembodiments, since the plurality of light-emitting diodes 10 can beenergized by a simple configuration using relatively inexpensive memberssuch as the at least one substrate 4 and the at least one electric wire8 instead of relatively expensive members such as a printed circuitboard and a lead frame, light-emitting devices which use thelight-emitting diodes 10 and which are less expensive than conventionallight-emitting devices can be provided.

[Light-Emitting Device According to a Sixth Embodiment]

FIGS. 6A-6C are diagrams showing a schematic configuration of alight-emitting device according to a sixth embodiment, in which FIG. 6Ais a perspective view, FIG. 6B is a partially enlarged view which showsan enlargement of a portion denoted by A in FIG. 6A, and FIG. 6C is adiagram showing a cross section taken along B-B in FIG. 6B.

As shown in FIGS. 6A-6C, the light-emitting device according to thesixth embodiment comprises a substrate 4 having a plurality of throughholes 42, a pair of electric wires 8 provided on a rear surface side ofthe substrate 4, and a plurality of light-emitting diodes 10.

In this embodiment, the pair of electric wires 8 is constituted by apair of an anode electric wire 8 a and a cathode electric wire 8 b. Inaddition, with the anode electric wire 8 a and the cathode electric wire8 b, respective portions to which the plurality of light-emitting diodes10 are mounted are bent so as to project to a front surface side of thesubstrate 4 from a rear surface side of the substrate 4 through thethrough holes 42 and then again pass through the through holes 42 toreturn to the rear surface side of the substrate 4. The plurality oflight-emitting diodes 10 are provided on the front surface side of thesubstrate 4 and positive and negative electrodes of the plurality oflight-emitting diodes 10 are respectively connected to the anodeelectric wire 8 a and the cathode electric wire 8 b.

Therefore, with the light-emitting device according to the sixthembodiment, a plurality of portions of the electric wires 8 provided onthe rear surface side of the substrate 4 communicates to the frontsurface side of the substrate 4 at the plurality of through holes 42provided in the substrate 4, and the plurality of light-emitting diodes10 provided on the front surface side of the substrate 4 arerespectively mounted to the respective portions of the electric wires 8which communicate to the front surface side of the substrate 4.

With the light-emitting device according to the sixth embodiment, sincethe plurality of light-emitting diodes 10 can be energized withouthaving to use a printed circuit board or a lead frame which isconsidered to be one of the reasons why conventional light-emittingdevices are expensive, light-emitting devices which use thelight-emitting diodes 10 and which are less expensive than conventionallight-emitting devices can be provided. Therefore, various forms oflighting including general lighting fixtures can be realized in aninexpensive and highly efficient manner.

In addition, with the light-emitting device according to the sixthembodiment, since the electric wires 8 are provided on the rear surfaceside of the substrate 4, freedom of wiring and arrangement of wiresincreases. Therefore, complicated circuits for individually driving theplurality of light-emitting diodes 10 or driving the plurality oflight-emitting diodes 10 in arbitrary groups can be readily formed.Thus, the functionality of the light-emitting device can be enhanced inan inexpensive manner.

[Light-Emitting Device According to a Seventh Embodiment]

FIGS. 7A-7C are diagrams showing a schematic configuration of alight-emitting device according to a seventh embodiment, in which FIG.7A is a perspective view, FIG. 7B is a partially enlarged view whichshows an enlargement of a portion denoted by A in FIG. 7A, and FIG. 7Cis a diagram showing a cross section taken along B-B in FIG. 7B.

As shown in FIGS. 7A-7C, in the light-emitting device according to theseventh embodiment, at least one electric wire 8 comprises a pluralityof electric wires (an electric wire 8 a, an electric wire 8 b, anelectric wire 8 c, an electric wire 8 d, . . . ). Each electric wire 8(the electric wire 8 a, the electric wire 8 b, the electric wire 8 c,the electric wire 8 d, . . . ) has one end and another end respectivelywhich project to a front surface side of the substrate 4 from a rearsurface side of the substrate 4 through the through holes 42 and whichare folded toward the front surface side of the substrate 4. A pluralityof light-emitting diodes 10 are provided on the front surface side ofthe substrate 4 and positive and negative electrodes of the plurality oflight-emitting diodes 10 are respectively connected to one end of oneelectric wire (for example, an electric wire 8 a) among the plurality ofelectric wires 8 and another end of another electric wire (for example,an electric wire 8 b) among the plurality of electric wires 8.

In a similar manner to the light-emitting device according to the sixthembodiment, with the light-emitting device according to the seventhembodiment, a plurality of portions of the electric wires 8 provided onthe rear surface side of the substrate 4 communicate to the frontsurface side of the substrate 4 at the plurality of through holes 42provided in the substrate 4, and the plurality of light-emitting diodes10 provided on the front surface side of the substrate 4 arerespectively mounted to the respective portions of the electric wires 8which communicate to the front surface side of the substrate 4.

While the plurality of light-emitting diodes 10 can be connected inparallel with the light-emitting device according to the sixthembodiment, the plurality of light-emitting diodes 10 can be connectedin series with the light-emitting device according to the seventhembodiment. By combining light-emitting devices according to the sixthand seventh embodiments, the plurality of light-emitting diodes 10 canbe connected in series-parallel, parallel-series, and the like.

[Light-Emitting Device According to an Eighth Embodiment]

FIGS. 8A-8C are diagrams showing a schematic configuration of alight-emitting device according to an eighth embodiment, in which FIG.8A is a perspective view, FIG. 8B is a partially enlarged view whichshows an enlargement of a portion denoted by A in FIG. 8A, and FIG. 8Cis a diagram showing a cross section taken along B-B in FIG. 8B.

As shown in FIGS. 8A-8C, in the light-emitting device according to theeighth embodiment, at least one electric wire 8 comprises an anodeelectric wire 8 a and a cathode electric wire 8 b. The anode electricwire 8 a and the cathode electric wire 8 b traverse opening planes ofthrough holes 42 on a rear surface side of the substrate 4. A pluralityof light-emitting diodes 10 are provided in the through holes 42, andpositive and negative electrodes of the plurality of light-emittingdiodes 10 are respectively connected to the anode electric wire 8 a andthe cathode electric wire 8 b.

In a similar manner to the light-emitting device according to the sixthembodiment, with the light-emitting device according to the eighthembodiment, a plurality of portions of the electric wires 8 provided onthe rear surface side of the substrate 4 communicate to the frontsurface side of the substrate 4 at the plurality of through holes 42provided in the substrate 4, and the plurality of light-emitting diodes10 provided on the front surface side of the substrate 4 arerespectively mounted to the respective portions of the electric wires 8which communicate to the front surface side of the substrate 4.

With the light-emitting devices according to the sixth to eighthembodiments described above, a resist, an etching material, a resiststripper, a plating solution, and respective recovery units thereof(refer to an additive method, a subtractive method, or the like) whichare considered necessary for manufacturing a printed wiring board becomeunnecessary and the need for a tie-bar section and the like which areconsidered necessary for a light-emitting device using a lead frame isalso eliminated. Thus, the waste that is conventionally produced whenmanufacturing a light-emitting device can now be reduced and anenvironmentally-friendly light-emitting device can be manufactured.

With the light-emitting devices according to the sixth to eighthembodiments described above, a light-emitting diode from the pluralityof light-emitting diodes 10, a protective element such as a Zener diode,a connector, a combination thereof and the like can be mounted to theelectric wires 8 on the rear surface side of the substrate 4.Accordingly, since the irregularities of the front surface side of thesubstrate 4 are reduced, the insulating layer 6 can be made thinner, thecost of the insulating layer 6 can be reduced, and a wider lightdistribution angle can be realized.

Hereinafter, the respective members of the present discloser will bedescribed.

[Substrate 4]

As the substrate 4, for example, members with a plate shape, a sheetshape (a tape shape or a film shape), a rod shape, a pipe shape, a wireshape, or the like made of aluminum, copper, iron, an alloy thereof, orother materials (including glass, wood, and plastic) can be used.Examples of a shape of the substrate 4 in plan view include a reedshape, a rectangular shape, a polygonal shape, a circular shape, a fanshape, and a donut shape.

As described earlier, since a printed circuit board need not be used asthe substrate 4 in the embodiments, a light-emitting device which usesthe light-emitting diodes 10 and which is less expensive thanconventional light-emitting devices can be provided.

A printed circuit board having one or more curve such as a circularshaped circuit board is fabricated by cutting the shaped circuit boardout from a square printed circuit board or the like, and a considerableamount of waste is created during the cut. Therefore, a curved printedcircuit board is more expensive than a square printed circuit board orthe like. However, according to the embodiments, since inexpensivemembers made of aluminum, copper, iron, an alloy thereof, or othermaterials (including glass, wood, and plastic) can be used as thesubstrate 4, an inexpensive light-emitting device can be provided evenif the substrate 4 has one or more curve to be shaped like a circular.

A size of the substrate 4 is not particularly limited and various sizesof the substrate 4 can be adopted in accordance with the intended use ofthe light-emitting device. For example, when the light-emitting deviceis used as a light source of a lighting device to replace astraight-tube fluorescent lamp, a rectangular member with a length of 30mm to 50 mm in a short direction and a length of 300 mm to 1200 mm in alongitudinal direction can be used as the substrate 4.

Favorably, a member with flexibility (for example, a member with a filmshape, a sheet shape, or the like) is used as the substrate 4. In thisway, a light-emitting device can be manufactured by a roll-to-rollprocess, and a light-emitting device that is even more inexpensive canbe provided. By bending the substrate 4, the substrate 4 can also beused in a circular fluorescent lamp.

For example, an insulating film with a thickness of 10 μm to 300 μm canbe used as the member with flexibility. Examples of materials for theinsulating film include resin films made of polyethylene terephthalate(PET), polyethylene naphthalate (PEN), polyetherimide (PEI),polyphenylene sulfide (PPS), liquid crystal polymer (LCP), and polyimide(PI). A light-emitting device that is even more inexpensive can beprovided by using PET or PEN that is particularly inexpensive amongthese materials. In addition, the use of PI which has high heatresistance as the material of the insulating film enables thelight-emitting diodes 10 to be mounted to the substrate 4 using soldermaterial or the like. Thus, a light-emitting device that is even moreinexpensive can be provided.

While the resin film can be transparent or colored, favorably, the resinfilm has enhanced optical reflectivity with respect to visible lightsuch as a resin film containing an optically reflective material or aresin film subjected to a microcellular foaming process.

While conductive property, flexibility, transparency, and the like ofthe substrate 4 do not particularly matter, the substrate 4 favorablyhas low or no elasticity. In this way, after setting the electric wire 8on the substrate 4, the adhesion between the substrate 4 and theelectric wire 8 can be secured to prevent warping of the substrate 4from occurring. In addition, the stress due to stretching or contractionof the substrate 4 can be prevented from acting on a portion of theelectric wire 8 to which the light-emitting diode 10 is connected.

In one example of the substrate 4 with low elasticity, the elasticity ofthe substrate 4 is approximately equal to the elasticity of the electricwire 8. Examples where the elasticity of the substrate 4 isapproximately equal to the elasticity of the electric wire 8 include acase where a copper thin plate is used as the substrate 4 and a copperwire is used as the electric wire 8 and a case where an aluminum plateis used as the substrate 4 and a copper-clad aluminum wire is used asthe electric wire 8.

Favorably, a surface of the substrate 4 is coated with a metal with highoptical reflectivity such as Ag or Al, a white resist made of a siliconeresin containing titanium oxide, a metal-oxide composite film, or thelike. In this way, luminous efficiency of the light-emitting device canbe increased.

A groove 18 can be provided on the substrate 4 or the insulating layer 6(to be described later). In this way, the electric wire 8 can be fittedin the groove 18 and kept in place. Therefore, the electric wire 8 canbe fixed by being embedded in the substrate 4, and the manufacture canbe simplified and a more inexpensive light-emitting device can beprovided.

[Insulating Layer 6]

When the substrate 4 has conductive property, the insulating layer 6 isfavorably provided on a surface on which the electric wire 8 isprovided. While any film can be used as the insulating layer 6 as longas the film has insulating property, the insulating layer 6 favorablyhas high optical reflectivity. In this way, the light outputted from thelight-emitting diode 10 can be efficiently reflected by the surface ofthe substrate 4. As the insulating layer 6 with high opticalreflectivity, an insulating layer containing a white filler or a whitepowder can be used for example. More specifically, a silicone resin or aresist containing TiO₂, a white resist made of a silicone resincontaining titanium oxide, a metal-oxide composite film such as analumite, and the like can be used. In addition, favorably, theinsulating layer 6 has high heat resistance and high light resistance.Members with shapes other than a film shape can be used as theinsulating layer 6.

The insulating layer 6 can be provided across almost the entire area ofa surface of the substrate 4 or provided in the limited areassurrounding the through holes 42.

[Electric Wire 8]

While various members having conductive property can be used as theelectric wire 8, in particular, a member with superior conductiveproperty is favorably used. For example, a metal wire with lowelectrical resistivity such as Cu, Au, Al, and Ag or a compositematerial thereof (a copper-clad aluminum wire, an alloy wire, or thelike) can be favorably used. In addition, a member that is readily bentis favorable. Furthermore, a member that is less susceptible to damage(less susceptible to fatigue) even when bent is particularly favorable.A noble metal plating using Pd, Pt, Ag, or the like or tin-based platingcan be applied to the electric wire 8. In particular, since Ag-platingproduces high optical reflectivity, the brightness of the light-emittingdevice can be improved and is therefore favorable. For plating of theabove, plating with good compatibility with connecting members thatconnect the positive and negative electrodes of the light-emitting diode10 and the electric wire 8 to each other is favorably used. For example,when a solder material is used as the connecting member, an electricwire with noble metal plating or tin-based plating is favorably used asthe electric wire 8.

As the electric wire 8, a coated electric wire in which a metal wire iscoated by an insulating member can be used. In this case, the insulationcoating on the insulation-coated electric wire that is exposed on thefront surface side (or communicates with the front surface side) of thesubstrate 4 is removed by polishing or heat generated by an air heater,solder, or light to expose a core wire of the insulation-coated electricwire and to mount the light-emitting diode 10 to the exposed core wire.By using a coated electric wire, a plurality of electric wires 8 can bebrought into contact with each other. Thus, various circuits can beassembled. A coated electric wire that uses an epoxy-based transparentresin containing a white resist or a white filler as aninsulating/coating material can be favorably used as the electric wire 8since the coating material has high reflectivity. As the coated electricwire, for example, magnet wires (an enameled wire, a rectangular copperwire, a streamlined wire, parallel wires, a copper-clad aluminum wire,or a fiber-covered or paper-covered copper winding wire) or the like canbe used.

As the electric wire 8, a member created by covering a surface of astring that is an insulator with a conductor and further covering theconductor with an insulator can also be used. By using such a member asthe electric wire 8, a plurality of electric wires 8 can be brought intocontact with each other in a similar manner to using a coated electricwire. Therefore, various circuits can be assembled and a lightweightlight-emitting device can be realized.

For example, a rectangular wire (a wire with a near-rectangular crosssection) or a circular wire (a wire with a near-circular cross section)can be used as the electric wire 8. The use of a rectangular wireenables a wider joining area to be secured between the substrate 4 andthe light-emitting diode 10. When using a circular wire, by partiallyflattening respective portions of the electric wire 8 to which thelight-emitting diodes 10 are to be mounted using a press or a roller,the areas of the portions on the electric wire 8 to be connected to thelight-emitting diode 10 increase. Thus, the light-emitting diode 10 canbe more readily mounted to the electric wire 8. The electric wire 8 canbe an aggregate of a plurality of wire rods such as a twisted wire.

In a case where a circular wire is used, by using a plurality of thincircular wires as a single group (by using as a single electric wire),the light-emitting diode 10 can be readily mounted to the electric wire8.

Forming a single group with three or more electric wires 8 (inparticular, circular wires or the like) and using the single group as anelectrode with one polarity (in other words, to use as though a singleelectric wire 8), the stability of the light-emitting diode 10 mountedon the electric wires 8 can be improved. Thus, the light-emitting diode10 can be stably mounted on the electric wires 8. Specifically, byarranging a plurality of electric wires 8 parallel to each other on thesubstrate 4 at intervals that are shorter than a width of an electrodeof the light-emitting diode 10 or by arranging the plurality of electricwires 8 parallel to each other on the substrate 4 so as to come incontact with each other, the plurality of electric wires 8 can be usedas an electrode with one polarity.

Three or more electric wires 8 which are used as a single group caninclude an electric wire 8 that is not electrically connected to thelight-emitting diode 10. For example, when using three electric wires 8as a single group, the two electric wires 8 among the three electricwires 8 can be electrically connected to the light-emitting diode 10,and the one remaining electric wire 8 can be exclusively used to improvethe stability of the light-emitting diode 10 without being electricallyconnected to the light-emitting diode 10.

A shape, dimensions, and the like of the electric wire 8 are notparticularly limited. For example, depending on properties required forthe light-emitting device, a size of the light-emitting diode 10 to bemounted, and the like, a thickness or a width of the electric wire 8 canrange between several tenths of mm to several mm. For example, anelectric wire 8 with a thickness ranging from 0.1 mm to 2 mm and alength ranging from 1 mm to 5 m can be used. However, since an enameledwire or the like has low reflectivity, generally, the enameled wire maybecome an absorption source of the light in the light-emitting device.Therefore, when using an enameled wire or the like as the electric wire8, a diameter of the electric wire 8 is favorably narrower than thelight-emitting diode 10 (favorably narrower than a positive electrode ora negative electrode of the light-emitting diode 10). In this way, theefficiency of a light-emitting device can be increased and the weight ofthe light-emitting device can be reduced. In addition, the material costfor the light-emitting device can be reduced.

When mounting the light-emitting diode 10 to the electric wire 8, anelectrode of the light-emitting diode 10 is connected to an electrodeprovided on the electric wire 8. The electrode on the electric wire 8,for example, can be formed by the following methods.

Example of Forming an Electrode Example 1

FIG. 9 is a schematic plan view showing an example (Example 1) of amethod of forming electrodes on one or more electric wire 8.

As shown in FIG. 9, this example uses a coated electric wire (circularwire) as the electric wire 8. When a coated electric wire (circularwire) is used as the electric wire 8, for example, a coating 81 (aregion denoted by X in FIG. 9) of the coated electric wire is removed bya half-cut made by a cutting tool (for example, a dicer or a Leutor),and the portion where the coating 81 has been removed (a region denotedby Y in FIG. 9) is cut by a full-cut. A portion where the coating 81 hasbeen removed, in other words, a core wire 82 which remains after thecut, becomes the electrode on the electric wire 8 which is connected tothe electrode of the light-emitting diode 10.

Example of Forming an Electrode Example 2

FIG. 10 is a schematic plan view showing an example (Example 2) of amethod of forming electrodes on one or more electric wire 8.

As shown in FIG. 10, in a similar manner to the example described above,this example also uses a coated electric wire (circular wire) as theelectric wire 8. In this example, a portion where the coating has beenremoved, in other words, the core wire 82 which remains after the cut,is bent, and the bent portion becomes the electrode on the electric wire8 which is connected to the electrode of the light-emitting diode 10.Bending the electric wire 8 in this manner increases the area of theelectrode (the core wire 82 shown in FIGS. 9 and 10 from which thecoating 81 has been removed) on the electric wire 8 which is connectedto the electrode of the light-emitting diode 10. Therefore, for example,when the electric wire 8 is a fine wire or the like, the electricalcontact between the light-emitting diode 10 and the electric wire 8 canbe more easily secured.

In the examples (Examples 1 and 2) of a method of forming an electrodeon the electric wire 8 described above, in addition to a method using adicer, methods such as laser processing and punching can be used to cutthe electric wire 8. By inserting a metal plate to be removed afterprocessing between the electric wire 8 and the substrate 4 or by cuttingthe electric wire 8 on a processing stage and subsequently transferringthe electric wire 8 to the substrate 4, the electric wire 8 can be cutwithout damaging the substrate 4.

Example of Forming an Electrode Example 3

FIGS. 11A-11C are diagrams showing an example (Example 3) of a method offorming electrodes on one or more electric wire 8.

As shown in FIGS. 11A-11C, this example uses coated electric wires(rectangular wires) as the electric wire 8. When coated electric wires(rectangular wires) are used as the electric wires 8, for example, theends of the coated electric wires are folded (FIG. 11A). An insulatinglayer 6 such as a white reflective material is provided on the substrate4 so that the folded portions are exposed (FIG. 11B). The foldedportions (the portions exposed from the insulating layer 6) becomeelectrodes on the electric wire 8 which are connected to the electrodesof the light-emitting diodes 10 (FIG. 11C).

In other words, each of the electric wires 8 is folded (an example ofbending), and it has a high portion (for example, a folded portion) anda low portion (for example, an unfolded portion) to provide a differencein height. The insulating layer 6 that is a white reflective material orthe like is provided so that the high portion (for example, the foldedportion) is exposed, and the high portion (for example, the foldedportion) is used as the electrode on each of the electric wires 8 whichis connected to the electrode of the light-emitting diode 10.

According to this example, by adjusting how much the electric wire 8 isto be folded, an area of the electric wire 8 which comes into contactwith the electrode of the light-emitting diode 10 can be readilyadjusted and an electrical contact between the light-emitting diode 10and the electric wire 8 can be secured more readily.

Example of Forming an Electrode Example 4

FIG. 12 is a diagram showing an example (Example 4) of a method offorming electrodes on one or more electric wire 8.

As shown in FIG. 12, in this example, a part of the substrate 4 israised. A portion on the electric wire 8 that is fixed to the raisedportion is used as the electrode and the light-emitting diode 10 ismounted thereto. In this way, since side surfaces of the light-emittingdiode 10 can be prevented from being covered by connecting members 20which connect the electrode of the light-emitting diode 10 and theelectric wire 8 to each other or the like, the light can be emitted fromthe light-emitting device at high brightness.

Even when through holes 42 are provided on the substrate 4, favorably,respective portions of the electric wire 8 to which the light-emittingdiodes 10 are to be mounted are bent (refer to FIGS. 6A-6C). In thisway, since the area of the electric wire 8 that is brought into contactwith the light-emitting diode increases, the light-emitting diode can bereadily mounted to the electric wire 8.

[Short-Circuit Electric Wire 22]

The short-circuit electric wire 22 is used to short-circuit differentelectric wires 8. For example, when a power source is provided on thesubstrate 4, the short-circuit electric wire 22 is used to short-circuitan electric wire 8 connected to a positive electrode of the power sourceand an electric wire 8 connected to a positive electrode of thelight-emitting diode 10, to short-circuit an electric wire 8 connectedto a negative electrode of the power source and an electric wire 8connected to a negative electrode of the light-emitting diode 10, toshort-circuit electric wires 8 connected to positive electrodes ofdifferent substrates 4 or electric wires 8 connected to negativeelectrodes of different substrates 4, and the like. The use of theshort-circuit electric wire 22 enables complicated circuits such as aseries-parallel circuit (refer to FIG. 4) in which each branch of aplurality of parallel circuits includes a plurality of light-emittingdiodes 10 connected in series and a parallel-series circuit (refer toFIG. 5) in which a plurality of parallel circuits having a plurality oflight-emitting diodes 10 connected in parallel is connected in series tobe readily constructed. Thus, desired light-emitting devices in whichlight-emitting diodes 10 are connected in various modes can beinexpensively provided.

A wire using the same material or having the same shape as the electricwire 8 can be used as the short-circuit electric wire 22. Examples ofshapes that can be used include a U-shaped pin. Connection of theshort-circuit electric wire 22 to the electric wire 8 can be performedusing connecting members such as a solder material or by fusing.

[Light-Emitting Diode 10]

As the light-emitting diode 10, for example, various elements such as asurface mount LED, a lamp LED, an LED chip, and a chip-size packaged LEDcan be used. An LED chip in which a blue light-emitting GaN-basedsemiconductor is stacked on a translucent substrate such as a sapphiresubstrate or the like can be particularly favorably used as thelight-emitting diode 10 by combining with a wavelength converting membersuch as a phosphor in a light-emitting device used as a lighting device.An inexpensive light-emitting device can be realized by using anunpackaged LED chip as the light-emitting diode 10.

The light-emitting diode 10 can be mounted to the electric wire 8 invarious modes (for example, flip-chip mounting, mounting by wirebonding, and mounting which combines die bonding and wire bonding). Inparticular, by flip-chip mounting, since the light-emitting diode 10 canbe placed on the substrate 4 and the light-emitting diode 10 and theelectric wire 8 can be electrically connected to one another at the sametime, mass productivity can be improved.

In addition to the front surface side of the substrate 4 and inside thethrough holes 42 of the substrate 4, the light-emitting diode 10 canalso be provided on the rear surface side of the substrate 4.

[Adhesive 12]

The substrate 4 and the electric wire 8 can be adhered to each other byone or more adhesive 12. The electric wire 8 and the light-emittingdiode 10 can be collectively adhered to the substrate 4 by the adhesive12.

Favorably, the adhesive 12 has high transparency, high heat resistanceand high light resistance, and has insulating property. Specifically,for example, transparent adhesives including an epoxy-based adhesive, asilicone-based adhesive, an acrylic adhesive, a modified silicone-basedadhesive, and a urethane-based adhesive can be used. A thermosettingadhesive or an ultraviolet-curable adhesive can be used. In particular,an acrylic ultraviolet-curable adhesive is favorable due to superiorheat resistance and superior light resistance, a high curing rate, andthe ability to simplify production lines. When a member with flexibilityis used as the substrate 4, favorably, a member with flexibility (forexample, a resin) is also used as the adhesive 12. In this way, when thesubstrate 4 bends, the stress applied to the light-emitting diode 10 orthe electric wire 8 can be reduced.

In addition, as the adhesive 12, a combination of a plurality ofadhesives can be used. For example, a thermosetting adhesive can be usedaround the through holes 42 and a thermoplastic adhesive can be used inother portions.

Favorably, the adhesive 12 contains a filler to enable adjustment ofoptical reflectivity, viscosity, and the like. By containing areflective material such as a white filler or a white powder made ofTiO₂, SiO₂, or the like, the light emitted from the light-emitting diode10 can be efficiently reflected on the substrate 4. As such fillers,oxides of Mg, Ca, Ba, Si, Al, Ti, Zr, rare-earth elements and mixturesthereof, and compounds thereof such as carbonates can be used. Fillersenable efficiency of the light-emitting device to be improved and shapecontrol of the adhesive 12 to be performed in a favorable manner.

The adhesive 12 can be provided in a part of a junction between thesubstrate 4 and the electric wire 8 or can be provided on the entirejunction. Providing the adhesive 12 in a part of a junction enables aninexpensive light-emitting device to be produced even if an expensivematerial (for example, a silicone resin) is used as the adhesive 12.

The adhesive 12 can be provided by methods such as dispensing and screenprinting. When a light-emitting device is manufactured by a roll-to-rollprocess, the adhesive 12 is favorably provided by printing.

The adhesive 12 can be a tape. Examples of tapes to be used as theadhesive 12 include an epoxy film tape, a polyimide film tape, a PTFEfilm tape, a polyester film tape, an acetate cloth tape, a cotton clothtape, and a vinyl tape.

[Sealing Member 14]

The light-emitting diode 10 can be sealed by a sealing member 14.

While various materials in accordance with the type of thelight-emitting diode 10 can be used as the sealing member 14, a materialwith insulating property, high transparency, high heat resistance, andhigh light resistance is favorable. For example, while an epoxy-basedresin, a silicone-based resin, a fluorine-based resin, or a resin thatis a mixture thereof can be used, a silicone-based resin is preferablyused. The sealing member 14 can be provided by various methods includingpotting, printing, and as a sheet.

The shape of the sealing member 14 is not limited. The sealing member 14can be provided in a desired shape by controlling viscosity andthixotropy of the sealing member 14. In particular, by providing thesealing member 14 in a domed shape, the extraction efficiency of lightof the light-emitting device can be improved.

The sealing member 14 can contain a wavelength converting member such asa phosphor. In this way, since various colors and emission spectra canbe provided, the needs of a wide range of markets including generallighting and liquid crystal TVs (liquid crystal backlight) can beaddressed.

Specifically, when the light-emitting diode 10 emits blue light,examples of the phosphor include a YAG phosphor that emits yellow light,a LAG phosphor or a SiAlON phosphor which emits green light, and a CASNphosphor or a SCASN phosphor which emits red light. By having thesealing member 14 contain these phosphors, a SiAlON phosphor that emitsgreen light and a CASN phosphor which emits red light can be combinedwith the light-emitting diode 10 that emits blue light. In this way, alight-emitting device which has high color reproducibility and which issuitable as a light source for backlighting can be realized. By havingthe sealing member 14 contain a combination of a LAG phosphor or a YAGphosphor that emits green or yellow light and a red light-emittingphosphor, a light-emitting device which has higher color renderingproperty (Ra) than when using one phosphor and which is capable ofemitting white light and light bulb-color light that are suitable as alight source for illumination can be realized.

The sealing member 14 can contain various fillers. The sealing member 14can also contain a light-diffusing member that scatters light. In thisway, a desired light distribution can be obtained or color unevennesscan be prevented. Examples of a material of the light-diffusing memberinclude TiO₂, SiO₂, Al₂O₃, MgO, MgCO₃, CaCO₃, Mg(OH)₂, and Ca(OH)₂.

The sealing member 14 can contain one or more kinds of filler. In thisway, color unevenness of the light-emitting device can be prevented andthe shape of the sealing member can be controlled. Examples of thefillers include inorganic fillers such as oxides of Mg, Ca, Ba, Si, Al,Ti, Zr, rare-earth elements and mixtures thereof, and carbonates andother compounds.

A method used to provide the sealing member 14 is not particularlylimited. The sealing member 14 can be provided by various methodsincluding molding using a casting case, potting on the light-emittingdiode 10, printing, transfer molding, compression molding, and injectionmolding. Sealing by the sealing member 14 can be performed individuallyon each of the light-emitting diodes 10 (refer to FIGS. 1 to 8) orperformed collectively on a plurality of the light-emitting diodes 10.

[Embankment Portion 16]

The sealing member 14 can be enclosed by an embankment portion 16. Withthe embankment portion 16, outflow or the like of the sealing member 14can be prevented when sealing the light-emitting diode 10 with thesealing member 14, and the sealing member 14 can be readily formed.

For example, a member with high reflectivity is favorably used as theembankment portion 16. Specifically, for example, in the case of resins,a white resin with high heat resistance and high light resistance andcontaining a white filler such as TiO₂ or SiO₂ can be favorably used asthe embankment portion 16. In the case of ceramics, a frame made ofAl₂O₃ or TiO₂, an Al-deposited or Ag-deposited glass frame, or the likecan be favorably used as the embankment portion 16.

A member with a large angle of contact with the sealing member 14 isfavorably used as the embankment portion 16. In this way, a height ofthe sealing member 14 can be adjusted when forming the sealing member 14and the light distribution of the light-emitting device can becontrolled.

[Connecting Member 20]

As the connecting member 20 which connects the light-emitting diode 10and the electric wire 8 to each other, a conductive joining materialincluding solders such as Au—Sn, Sn—Cu—Ag, Sn—Cu, Sn—Bi, and Sn—Zn,anisotropic conductive pastes, silver pastes, copper pastes, and carbonpastes can be used.

However, when the light-emitting diode 10 and the electric wire 8 areconnected to each other by flip-chip mounting as in the illustratedexamples, bumps can be used as the connecting member in addition to themembers described above. Au and an alloy thereof can be preferably usedas the bumps.

When the light-emitting diode 10 and the electric wire 8 are connectedto each other by wire bonding unlike in the illustrated examples, a wirecan also be used as the connecting member. As the wire, a fine wire madeof a metal such as Au, Ag, Al, and Cu, an alloy thereof, or a platedalloy can be preferably used. When the light-emitting diode 10 and theelectric wire 8 are connected to each other by wire bonding, a portionwhere the light-emitting diode 10 is placed is not limited. In thiscase, for example, the light-emitting diode 10 can be placed on thesubstrate 4 at a portion separated from the electric wire 8 or betweenelectric wires 8.

For example, an electrode of the light-emitting diode 10 and theelectric wire 8 can be directly connected to each other without using aconnecting member, by ultrasonic welding, fusing, or the like.

When the light-emitting diode 10 is bonded or adhered to the electricwire 8 without performing an electric connection, a thermosetting resinsuch as an epoxy resin or a silicone resin with insulating property canbe used.

[Other]

Besides the above, a power-supply connector or a protective element (forexample, a Zener diode) can also be provided on the electric wire 8fixed on the substrate 4.

A position of the power-supply connector and a routing method of theelectric wire 8 can be altered as appropriate depending on the intendeduse of the light-emitting device. For example, when the light-emittingdevice is used as a light source of a lighting device to replace astraight-tube fluorescent lamp, since a power-supply terminal must beprovided at one end, favorably, the electric wire 8 is routed to the oneend of the substrate 4 and positive and negative electrodes are providedat the one end.

As the Zener diode, a packaged Zener diode or the like can be used aswell as a Zener diode chip.

Hereinafter, examples will be described.

First Example

An example of a method of manufacturing the light-emitting device shownin FIGS. 1A-1C will be described.

First, an aluminum plate (thickness 1 mm, width 16 mm, and length 706mm) is prepared as the substrate 4.

Next, a PI film (thickness 38 μm) with insulating property is attachedas the insulating layer 6 at an entire one surface of the substrate 4 ora portion of the one surface of the substrate 4 where the electric wire8 is to be fixed on.

Next, a single copper-clad aluminum wire (φ50 μm) subjected to aninsulation coating process is linearly arranged as the electric wire 8on the insulating layer 6 to be parallel to a longitudinal direction ofthe substrate 4. In doing so, the electric wire 8 is fitted in thegroove 18 so as to be embedded halfway in the insulating layer 6.

Next, in order to have the substrate 4 and the electric wire 8 adhere toeach other, the adhesives 12 made of a TiO₂-containing silicone resinare applied on the electric wire 8 and on 12 portions on the substrate 4(specifically, on the insulating layer 6).

Each of the adhesives 12 applied on the substrate 4 has a circular shapewith a diameter of 10 mm and with a center positioned on the electricwire 8. A center-to-center distance of the circles is set to 58 mm.Since the light outputted from the light-emitting diode 10 spreads in acircular shape, by applying the adhesives 12 so as to conform to theshape, the adhesives 12 can be prevented from being applied in awasteful manner and a light-emitting device with improved light useefficiency can be inexpensively provided.

Next, by dispensing, TiO₂-containing silicone resin (white resin frame)with an annular (circular) shape that is 3 mm in diameter is formed asthe embankment portions 16 in regions where the adhesives 12 have beenapplied. The circular regions where the adhesives 12 have been appliedand the embankment portions 16 are concentrically arranged.

Next, the adhesives 12 and the embankment portions 16 are thermallyhardened.

Next, near the center of a circular region where the each of adhesives12 has been applied, the adhesives 12 are partially removed and theelectric wire 8 is half-cut (at a cut width of 1 mm and to a depth thatreaches the center of the electric wire 8) by a dicer to remove theinsulation coating on the surface of the electric wire 8.

Next, the blade of the dicer is replaced to make a full-cut (cut width0.1 mm, cut depth 0.06 mm) of the electric wire 8 whose insulationcoating has been removed and whose core is exposed.

Next, solder pastes are dispensed as the connecting members 20 inportions of the electric wire 8 whose insulation coating has beenremoved and whose core is exposed.

Next, a plurality of LED chips (with a size of 1200 μm on a side in planview) are mounted as the light-emitting diodes 10 by a mounter to acenter portions of the regions where the adhesives 12 have been appliedrespectively, and each of the light-emitting diodes 10 are arranged atportions where the connecting members 20 are dispensed so that anelectrode of the light-emitting diode 10 opposes the electric wire 8. AZener diode and a connector are mounted to the electric wire 8.

Next, the connecting members 20 are melted by a reflow furnace toelectrically connect the light-emitting diodes 10, the Zener diode, andthe connector to the electric wire 8.

Next, the flux residue of the connecting members 20 is cleaned andremoved.

Next, a transparent silicone-based resin with low viscosity and highlight resistance is provided under each of the light-emitting diodes 10as underfill.

Next, the sealing members 14 that is a translucent silicone resincontaining a YAG phosphor is potted on each of the light-emitting diodes10 and inside the embankment portions 16. In addition, a sealing member14 is also potted on the Zener diode chip.

Next, the sealing members 14 are thermally hardened.

With the manufacturing method according to the first example, thelight-emitting device shown in FIGS. 1A-1C can be inexpensivelymanufactured.

Second Example

Next, an example of a method of manufacturing the light-emitting deviceshown in FIGS. 2A-2C will be described.

First, a copper thin plate (thickness 0.3 mm, width 16 mm, and length300 mm) is prepared as the substrate 4. Since a copper thin plate isused, the substrate 4 according to the second example has superior heatradiation.

Next, a white resist (thickness 38 μm) that is a TiO₂-containingsilicone resin is printed on an entire one surface of the substrate 4 asthe insulating layer 6.

Next, two copper wires (φ200 μm) are linearly arranged on the insulatinglayer 6 as the electric wires 8 so as to be parallel to each other. Indoing so, the electric wires 8 are fitted in the grooves 18 so as to beembedded halfway in the insulating layer 6. An interval between the twoelectric wires 8 is set to 0.2 mm.

Next, the adhesives 12 that are silicone resins including a white filleris applied on the electric wires 8 and the substrate 4 (morespecifically, the insulating layer 6). The adhesives 12 applied on thesubstrate 4 have a circular shape with a diameter of 5 mm and with acenter positioned between the two electric wires 8. A distance of thecircles is set to 12 mm. As described earlier, since the light outputtedfrom the light-emitting diode 10 spreads in a circular shape, byapplying the adhesive 12 so as to conform to the shape, the adhesives 12can be prevented from being applied in a wasteful manner and alight-emitting device with improved light use efficiency can beinexpensively provided.

Next, annular white frames with circular shapes that are 3 mm indiameter are formed as the embankment portions 16 by a method such asprinting and dispensing.

Next, the adhesives 12 and the embankment portions 16 are hardened.

Next, the adhesives 12 are partially removed and the electric wires 8are half-cut (at a cut width of 1 mm and to a depth that reaches thecenter of the electric wires 8) by a dicer to remove the insulationcoating of the electric wires 8.

Next, solder pastes are dispensed as the connecting members 20 inportions of the electric wires 8 whose insulation coating have beenremoved and whose cores are exposed.

Next, LED chips are mounted as the light-emitting diodes 10 by a mounterto center portions of the regions where the adhesives 12 have beenapplied, and the light-emitting diodes 10 are arranged at portions wherethe connecting members 20 are dispensed so that the electrodes of thelight-emitting diodes 10 oppose the electric wires 8 via the connectingmembers 20. A Zener diode and a connector are mounted to the electricwires 8.

Next, the connecting members 20 are melted by a reflow furnace toelectrically connect the light-emitting diodes 10, the Zener diode, andthe connector to the electric wires 8.

Next, the flux residue of the connecting members 20 is cleaned andremoved.

Next, the sealing members 14 containing a phosphor are potted on thelight-emitting diodes 10.

Subsequently, the sealing members 14 are thermally hardened.

With the manufacturing method according to the second example, thelight-emitting device shown in FIGS. 2A-2C can be inexpensivelymanufactured.

Third Example

Next, an example of a method of manufacturing the light-emitting deviceshown in FIGS. 3A-3C will be described.

First, an electrogalvanized steel plate (thickness 1 mm, width 16 mm,and length 300 mm) is prepared as the substrate 4.

Next, a PET film (thickness 38 μm) is attached to an almost entire onesurface of the substrate 4 as the insulating layer 6.

Next, an enameled wire with a bonding layer (for example, a type 0magnet wire with a size of 0.1 mm) is wound in a single layer around thesurface of the substrate 4 as the electric wire 8 from one end toanother end of the substrate 4 so that a plurality of portions parallelto one another appear on short-direction side surfaces of the substrate4. In doing so, the electric wire 8 is fitted in the grooves 18 providedon the side surfaces of the substrate 4. A distance between the electricwires 8 is set to 29.33 mm.

Next, in order to fix the substrate 4 and the electric wire 8 to eachother, the substrate 4 wounded with the electric wire 8 is heated atapproximately 120 to 220 degrees. The heating is favorably performedunder pressure to prevent the electric wire 8 from detaching from thesubstrate 4.

Next, the adhesives 12 that are silicone resins including a white filleris applied on the electric wire 8 and the substrate 4 (morespecifically, the insulating layer 6). The adhesives 12 applied on thesubstrate 4 are first applied so as to cover the electric wire 8 in ashort direction of the substrate 4 and subsequently applied so as toform circles having centers at centers of the substrate 4 in the shortdirection. As described earlier, since the light outputted from thelight-emitting diode 10 spreads in a circular shape, by applying theadhesives 12 so as to conform to the shape, the adhesives 12 can beprevented from being applied in a wasteful manner and a light-emittingdevice with improved light use efficiency can be inexpensively provided.

Next, an annular embankment portions 16 are formed.

Next, the adhesives 12 and the embankment portions 16 are hardened.

Next, the adhesives 12 are partially removed at center portions of theembankment portions 16 and the electric wire 8 is half-cut (at a cutwidth of 1 mm and to a depth that reaches the center of the electricwires 8) by a dicer to remove the insulation coating of the electricwire 8. A winding start portion and a winding end portion of theelectric wire 8 at ends of the substrate 4 are also half-cut by thedicer.

Next, the blade of the dicer is replaced to make a full-cut (cut width0.1 mm, cut depth 0.11 mm) of the electric wire 8 whose insulationcoating has been removed and whose core is exposed.

Next, solder pastes are dispensed as the connecting members 20 inportions of the electric wire 8 whose insulation coating have beenremoved and whose core are exposed.

Next, LED chips (1200 μm on a side) are mounted as the light-emittingdiodes 10 by a mounter to center portions of the embankment portions 16,and the light-emitting diodes 10 are arranged in flip-chip mounting atportions where the connecting members 20 are dispensed so that theelectrodes of the light-emitting diodes 10 oppose the electric wire 8via the connecting members 20. Another electric wire 8 parallel to thewinding start portion and a winding end portion of the electric wire 8is provided at ends of the substrate 4 and a Zener diode and a substrateare mounted to the other electric wire 8.

Next, the connecting members are melted by a reflow furnace toelectrically connect the light-emitting diode 10, the Zener diode, andthe connector to the electric wires 8.

Next, the flux residue of the connecting members 20 is cleaned andremoved.

Next, the sealing members 14 containing a phosphor are potted on thelight-emitting diodes 10. The sealing member 14 is also potted on theZener diode.

Next, the sealing members 14 are hardened.

With the manufacturing method according to the third example, thelight-emitting device shown in FIGS. 3A-3C can be inexpensivelymanufactured.

Fourth Example

Next, an example of a method of manufacturing the light-emitting deviceshown in FIG. 4 will be described.

First, PI film (thickness 0.38 mm, width 16 mm, and length 706 mm) areprepared as the substrates 4. As described earlier, since the insulatinglayers 6 are provided on the surfaces of the substrates 4, thesubstrates 4 do not appear in FIG. 4.

Next, white resists that are a TiO₂-containing silicone resin areprinted on an approximately entire one surfaces of the substrate 4 asthe insulating layers 6.

Next, three enameled wires (φ50 μm) are linearly arranged on theinsulating layers 6 as the electric wires 8 so as to be parallel to eachother. The electric wires 8 are fixed on the substrates 4 withinsulating tapes. Intervals between the three electric wires 8 are setto 1 mm.

Next, by printing, white annular frames that are shaped as circles withdiameters of 3 mm are formed on the three electric wires 8 as theembankment portions 16. In doing so, the embankment portions 16 areformed so that centers of the circles of the embankment portions 16 arepositioned above the center electric wires 8 among the three electricwires 8.

Next, the embankment portions 16 are hardened.

Next, the electric wires 8 are half-cut (at a cut width of 1 mm and to adepth that reaches the center of the electric wires 8) by a dicer toremove the insulation coating of the electric wires 8. Parallel electricwires 8 formed at ends of the substrates 4 are also half-cut by thedicer.

Next, the blade of the dicer is replaced to make a full-cut (cut width0.1 mm, cut depth 0.06 mm) of the electric wires 8 whose insulationcoating has been removed and whose core is exposed.

Next, solder pastes are dispensed as the connecting members in a portionof the electric wires 8 whose insulation coating have been removed andwhose core are exposed.

Next, LED chips are mounted as the light-emitting diode 10 by a mounterto a center portions of the embankment portions 16. Specifically, thelight-emitting diodes 10 are arranged in portions where the connectingmembers are dispensed. A Zener diode and a connector are mounted to theelectric wires 8. A short-circuit electric wires 22 are mounted to theelectric wires 8 to form a series-parallel circuit in which each branchparallel circuit is made up of six light-emitting diodes 10 connected inseries.

Next, the connecting members are melted by a reflow furnace toelectrically connect the light-emitting diodes 10, the Zener diode, theconnector, and the short-circuit electric wires 22 to the electric wires8.

Next, the flux residue of the connecting member is cleaned and removed.

Next, the sealing members 14 containing a phosphor are potted on thelight-emitting diodes 10. The sealing member 14 is also potted on theZener diode.

Next, the sealing members 14 are thermally hardened.

With the manufacturing method according to the fourth example, thelight-emitting device shown in FIG. 4 can be inexpensively manufactured.In particular, with the manufacturing method according to the fourthexample, a plurality of the light-emitting diodes 10 can beinexpensively connected in series-parallel using the short-circuitelectric wire 22. Accordingly, a light-emitting device with acomplicated circuit configuration can be inexpensively formed.

Fifth Example

Next, an example of a method of manufacturing the light-emitting deviceshown in FIG. 5 will be described.

First, a piece of aluminum foil (thickness 0.1 mm, width 30 mm, andlength 1200 mm) is prepared as the substrate 4. As described earlier,since the insulating layer 6 is provided on the surface of the substrate4, the substrate 4 does not appear in FIG. 5.

Next, the insulating layer 6 (thickness 20 μm) is formed on an entireone surface of the substrate 4 by an alumite treatment and sealing.

Next, after applying adhesives on surfaces of three tin-plated aluminumwires (φ100 μm), each of the tin-plated aluminum wires are linearlyprovided on the insulating layer 6 as the electric wires 8 so as to beparallel to a longitudinal direction of the substrate 4. Intervalsbetween the three electric wires 8 are set to 1 mm.

Next, adhesives containing a white filler are applied to the insulatinglayer 6 on the substrate 4. The applied adhesives have circular shapeswith diameters of 10 mm and with centers positioned on the electricwires 8. A center-to-center distance of the circles is set to 58 mm. Asdescribed earlier, since the light outputted from the light-emittingdiode 10 spreads in a circular shape, by applying the adhesives so as toconform to the shape, the adhesives can be prevented from being appliedin a wasteful manner and a light-emitting device with improved light useefficiency can be inexpensively provided.

Next, annular white frames with circular shapes that are 3 mm indiameter are formed as the embankment portions 16 by a method such asprinting or dispensing in a region where the adhesives have beenapplied. The circular regions where the adhesives have been applied andthe embankment portions 16 are concentrically arranged.

Next, the adhesives and the embankment portions 16 are hardened.

Next, the adhesives are partially removed at center portions of theregions where the adhesives have been applied to expose the electricwires 8. The adhesives are also removed from portions of electric wires8 formed parallel at ends of the substrate 4 to expose the electricwires 8.

Next, a full-cut (cut width 0.1 mm, cut depth 0.11 mm) of the exposedelectric wires 8 whose insulation coating have been removed is made by adicer. Subsequently, a full-cut (cut width 1 mm, cut depth 0.11 mm) ofpredetermined portion of the center electric wire 8 among the threeelectric wires 8 is made.

Next, solder pastes are dispensed as the connecting members in portionsof the exposed electric wires 8 whose insulation coating have beenremoved.

Next, LED chips (1200×500 μm) are mounted as the light-emitting diodes10 by a mounter to center portions of the regions where the adhesiveshave been applied, and the light-emitting diodes 10 are arranged atportions where the connecting members have been dispensed so thatelectrodes of the light-emitting diode 10 oppose the electric wires 8. AZener diode and a connector are mounted to the electric wires 8. Theshort-circuit electric wires 22 are mounted to the electric wires 8 toform a parallel-series circuit in which parallel circuits constituted byfour light-emitting diodes 10 connected in parallel are connected inseries.

Next, the connecting members are melted by a reflow furnace to connectthe light-emitting diodes 10, the Zener diode, the connector, and theshort-circuit electric wire 22 to the electric wires 8.

Next, the flux residue of the connecting members is cleaned and removed.

Next, the sealing members 14 containing a phosphor are potted on thelight-emitting diodes 10. The sealing members 14 are also potted on theZener diode.

Next, the sealing members 14 are hardened.

With the manufacturing method according to the fifth example, thelight-emitting device shown in FIG. 5 can be inexpensively manufactured.In particular, with the manufacturing method according to the fifthexample, a plurality of the light-emitting diodes 10 can beinexpensively connected in parallel-series using the short-circuitelectric wires 22. Accordingly, a light-emitting device with acomplicated circuit configuration can be inexpensively formed.

Sixth Example

Next, an example of a method of manufacturing the light-emitting deviceshown in FIGS. 6A-6C will be described with reference to FIGS. 13A-13E.FIGS. 13A-13E are partially enlarged views of a light-emitting deviceshowing a method of manufacturing a light-emitting device according to asixth example. As shown in FIGS. 13A-13E, the method of manufacturing alight-emitting device according to the sixth example includes thefollowing steps.

(First Step)

First, as shown in FIG. 13A, a substrate 4 with a plurality of throughholes 42 is prepared. An SUS304 thin plate with a thickness of 0.1 mm, awidth of 16 mm, and a length of 300 mm is used as the substrate 4.Elongate holes (length 1 mm, width 0.4 mm) are formed at intervals of12.5 mm at 24 portions on a center line of the substrate 4 to constitutethe through holes 42.

(Second Step)

Next, as shown in FIG. 13B, the electric wires 8 made up of a pair of ananode electric wire 8 a and a cathode electric wire 8 b are provided ona rear surface side of the substrate 4. In doing so, with the anodeelectric wire 8 a and the cathode electric wire 8 b, respective portionsto which the plurality of light-emitting diodes 10 are mounted are bentso as to project to a front surface side of the substrate 4 from a rearsurface side of the substrate 4 through the through holes 42 and thenagain pass through the through holes 42 to return to the rear surfaceside of the substrate 4.

More specifically, on the rear surface side of the substrate 4, twoenameled wires (rectangular wires; thickness 0.15 mm, width 0.5 mm) arelaid as a pair of electric wires 8 so as to sandwich a center line ofthe substrate 4 and passed through the through holes 42 to project fromthe front surface side of the substrate 4 by 0.15 mm. Subsequently, anepoxy-based adhesives are applied as adhesives to a region surroundingthe through holes 42 of the substrate 4 to fix the two electric wires 8to the substrate 4.

(Third Step)

Next, as shown in FIG. 13C, a silicone-based white resist is provided ata thickness of 10 to 20 μm as the insulating layer 6 on the frontsurface side of the substrate 4. Various application methods such asscreen printing and spray coating can be used.

Subsequently, an insulation coating (white resist and enamel) ofportions (width 0.5 mm, length approximately 0.3 mm) of the pair ofelectric wires 8 projected from the through holes 42 are removed by, forexample, a Leutor. In the sixth example, since the application thicknessis thinner than a projected amount of the electric wires 8, the portionswhere the insulation coating is to be removed can be readily identifiedeven after the insulating layer 6 is provided.

(Fourth Step)

Next, as shown in FIG. 13D, solder pastes are dispensed as connectingmembers at the portions where the insulation coating have been removed(48 portions), and 24 flip-chip mounting LED chips (length 0.8 mm, width0.3 mm) are mounted in a predetermined orientation (an orientation whichenables positive and negative electrodes to be respectively connected toone electric wire 8 and the other electric wire 8 among the pair ofelectric wires 8) as the light-emitting diodes 10 at the portions wherethe connecting members have been dispensed. The connecting members aremelted by a reflow furnace to connect the light-emitting diodes 10 tothe electric wires 8.

A protective element such as a Zener diode, a connector, and the likeare provided on the electric wires 8 on the rear surface side of thesubstrate 4.

(Fifth Step)

Next, as shown in FIG. 13E, flux is cleaned, an embankment portions 16are formed using an epoxy-based transparent resin containing a whitefiller, and a silicone-based resin mixed with a YAG phosphor are pottedand hardened as the sealing members 14.

Seventh Example

Next, an example of a method of manufacturing the light-emitting deviceshown in FIGS. 7A-7C will be described with reference to FIGS. 14A-14E.FIGS. 14A-14E are a partially enlarged views of a light-emitting deviceshowing a method of manufacturing a light-emitting device according to aseventh example. As shown in FIGS. 14A-14E, the method of manufacturinga light-emitting device according to the seventh example includes thefollowing steps.

(First Step)

First, as shown in FIG. 14A, a substrate 4 with a plurality of throughholes 42 is prepared. An SUS304 thin plate with a thickness of 0.1 mm, awidth of 16 mm, and a length of 300 mm is used as the substrate 4.Elongate holes (length 1 mm, width 0.4 mm) are formed at intervals of12.5 mm at 24 portions on a center line of the substrate 4 to constitutethe through holes 42.

(Second Step)

Next, as shown in FIG. 14B, on the rear surface side of the substrate 4,a single enameled wire (a rectangular wire; thickness 0.15 mm, width 0.5mm) is laid over a center line of the substrate 4 and passed through thethrough holes 42 to project from the front surface side of the substrate4 by 0.15 mm, and the projected portion is cut off. In this way, thesingle enameled wire is separated into a plurality of electric wires 8(an electric wire 8 a, an electric wire 8 b, an electric wire 8 c, anelectric wire 8 d, . . . ), and one end of each electric wire 8 (theelectric wire 8 a, the electric wire 8 b, the electric wire 8 c, theelectric wire 8 d, . . . ) and another end of each electric wire 8 (theelectric wire 8 a, the electric wire 8 b, the electric wire 8 c, theelectric wire 8 d, . . . ) are passed from the rear surface side of thesubstrate 4 through the through holes 42 to project from the frontsurface side of the substrate 4.

Subsequently, the projected one end and another end of each electricwires 8 (the electric wire 8 a, the electric wire 8 b, the electric wire8 c, the electric wire 8 d, . . . ) are folded toward the front surfaceside of the substrate 4, an epoxy-based adhesives are applied as theadhesives 12 in a region surrounding the through holes 42 of thesubstrate 4, and the one end and the another end of each electric wire 8(the electric wire 8 a, the electric wire 8 b, the electric wire 8 c,the electric wire 8 d, . . . ) are fixed to the substrate 4.

(Third Step)

Next, as shown in FIG. 14C, a silicone-based white resist is provided ata thickness of 10 to 20 μm as the insulating layer 6 on the frontsurface side of the substrate 4 and then hardened.

Subsequently, an insulation coating (white resist and enamel) of aportion (width 0.5 mm, length approximately 0.3 mm) of the one end andthe another end of each electric wire 8 (the electric wire 8 a, theelectric wire 8 b, the electric wire 8 c, the electric wire 8 d, . . . )that are projected from the through holes 42 is removed by a blade suchas a Leutor. In the seventh example, in a similar manner to the sixthexample, since the application thickness of the insulating layer 6 isthinner than a projected amount of the electric wires 8, portions wherethe insulation coating is to be removed can be readily identified evenafter application.

(Fourth Step)

Next, as shown in FIG. 14D, solder pastes are dispensed as connectingmembers at the portions where the insulation coating have been removed(48 portions), and 24 flip-chip mounting LED chips (length 0.8 mm, width0.3 mm) are mounted in a predetermined orientation (an orientation whichenables positive and negative electrodes to be respectively connected toone end of one electric wire 8 (for example, the electric wire 8 a) andanother end of another electric wire 8 (for example, the electric wire 8b)) as the light-emitting diodes 10 at the portions where the connectingmembers have been dispensed. The connecting members are melted by areflow furnace to electrically connect the light-emitting diodes 10 tothe electric wires 8.

A protective element such as a Zener diode, a connector, and the likeare provided on the electric wires 8 on the rear surface side of thesubstrate 4.

(Fifth Step)

Next, as shown in FIG. 14E, flux is cleaned, a annular (circular)embankment portions 16 which enclose the light-emitting diodes 10 inplan view are formed using an epoxy-based transparent resin containing awhite filler, and a silicone-based resins mixed with a YAG phosphor arepotted and hardened as the sealing members 14 on the inside of theembankment portion 16.

Eighth Example

Next, an example of a method of manufacturing the light-emitting deviceshown in FIGS. 8A-8C will be described with reference to FIGS. 15A-15D.FIGS. 15A-15D are a partially enlarged view of a light-emitting deviceshowing a method of manufacturing a light-emitting device according toan eighth example. As shown in FIGS. 15A-15D, the method ofmanufacturing a light-emitting device according to the eighth exampleincludes the following steps.

(First Step)

First, as shown in FIG. 15A, a substrate 4 with a plurality of throughholes 42 is prepared. A white polyphthalamide (PPA) plate with athickness of 2 mm, a width of 16 mm, and a length of 300 mm is used asthe substrate 4. Holes (with an upper surface diameter of 3 mm and abottom surface diameter of 1.4 mm) that are circular in plan view areformed at 12.5 mm intervals at 24 portions on a center line of thesubstrate 4 to constitute the through holes 42.

(Second Step)

Next, as shown in FIG. 15B, electric wires 8 made up of a pair of ananode electric wire 8 a and a cathode electric wire 8 b are provided ona rear surface side of the substrate 4. In doing so, the anode electricwire 8 a and the cathode electric wire 8 b are provided so as totraverse opening planes of the through holes 42 on a rear surface sideof the substrate 4.

More specifically, on the rear surface side of the substrate 4, twoenameled wires (rectangular wires; thickness 0.15 mm, width 0.5 mm) arelaid as a pair of electric wires 8 so as to sandwich a center line ofthe substrate 4 and to traverse opening planes of the through holes 42.An epoxy-based adhesives are applied as the adhesives to the substrate 4to fix the two electric wires 8 to the substrate 4.

(Third Step)

Next, as shown in FIG. 15C, an insulation coating (enamel) of a portion(width 0.5 mm, length approximately 0.3 mm) of the pair of electricwires 8 above the opening planes of the through holes 42 is removed by,for example, a Leutor. As shown in FIG. 15C, solder pastes are dispensedas connecting members at the portions where the insulation coating havebeen removed, and LED chips (length 0.8 mm, width 0.3 mm) havingpositive and negative electrodes formed on one primary surface aremounted in a predetermined orientation (an orientation which enables thepositive and negative electrodes to be respectively connected to oneelectric wire 8 and the other electric wire 8) as the light-emittingdiodes 10 at the portions where the connecting members have beendispensed. The connecting members are melted by a reflow furnace toconnect the light-emitting diodes 10 to the electric wires 8.

A protective element such as a Zener diode, a connector, and the likeare provided on the electric wires 8 on the rear surface side of thesubstrate 4.

(Fourth Step)

Next, as shown in FIG. 15D, after flux is cleaned, a silicone-basedresins mixed with a YAG phosphor are potted and hardened as the sealingmembers 14.

While rectangular wires are used as the electric wires 8 in the sixth,seventh, and eighth examples described above, circular wires can also beused. In this case, a lock stitch of a sewing machine which uses anupper thread and a lower thread can be applied so that the electric wire8 is passed through the through holes of the substrate 4, and byadjusting tension and sizes of an upper thread and a lower thread(enameled wires), the electric wire 8 can be projected from the throughholes 42 of the substrate 4 by a predetermined dimension. Specifically,the tension of the upper thread is set higher than that of the lowerthread so that an end of the electric wire 8 that is the lower thread isprojected from the substrate 4. At this point, by selecting a size andtension of the upper thread, a length by which the lower thread projectsfrom the substrate 4 can be adjusted.

While embodiments and examples have been described above, it is to beunderstood that the descriptions merely present examples and are not tobe construed as limiting the present invention in any way.

What is claimed is:
 1. A light-emitting device comprising: at least onesubstrate; at least one electric wire fixed to the substrate; and aplurality of light-emitting diodes mounted to the electric wire, whereineach of the plurality of light-emitting diodes is an LED chip, andwherein the light-emitting diodes on the substrate are sealedindividually or collectively by one or more sealing members.
 2. Thelight-emitting device according to claim 1, wherein a groove is providedon the substrate, and wherein the electric wire is fitted in the groove.3. The light-emitting device according to claim 1, wherein a portion ofthe electric wire is bent, and wherein the light-emitting diodes aremounted to the bent portion of the electric wire.
 4. The light-emittingdevice according to claim 1, wherein the electric wire comprises a highportion and a low portion, and wherein the light-emitting diodes aremounted to the high portion of the electric wire.
 5. A light-emittingdevice, comprising: at least one substrate having a plurality of throughholes; at least one electric wire provided on a rear surface side of thesubstrate; and a plurality of light-emitting diodes, wherein a pluralityof portions of the electric wire provided on the rear surface side ofthe substrate communicates with a front surface side of the substrate atthe plurality of through holes of the substrate, and wherein theplurality of light-emitting diodes is respectively mounted to therespective portions of the electric wire that communicate with the frontsurface side of the substrate.
 6. The light-emitting device according toclaim 5, wherein the at least one electric wire comprises an anodeelectric wire and a cathode electric wire, wherein respective portionsof the anode electric wire to which the plurality of light-emittingdiodes is mounted and respective portions of the cathode electric wireto which the plurality of light-emitting diodes is mounted are bent soas to project to the front surface side of the substrate from the rearsurface side of the substrate through the through holes and then againpass through the through holes to return to the rear surface side of thesubstrate, and wherein positive and negative electrodes of the pluralityof light-emitting diodes are respectively connected to the anodeelectric wire and the cathode electric wire.
 7. The light-emittingdevice according to claim 5, wherein the at least one electric wirecomprises a plurality of electric wires, wherein one end of eachelectric wire and another end of each electric wire pass through thethrough holes from the rear surface side of the substrate and project tothe front surface side of the substrate, and wherein positive andnegative electrodes of the plurality of light-emitting diodes arerespectively connected to the one end of one electric wire among theplurality of electric wires and the another end of another electric wireamong the plurality of electric wires.
 8. The light-emitting deviceaccording to claim 7, wherein the electric wires, which pass through thethrough holes from the rear surface side of the substrate and project tothe front surface side of the substrate, are folded toward the frontsurface side of the substrate.
 9. The light-emitting device according toclaim 5, wherein the at least one electric wire comprises an anodeelectric wire and a cathode electric wire, wherein the anode electricwire and the cathode electric wire traverse opening planes of thethrough holes on the rear surface side of the substrate, and wherein theplurality of light-emitting diodes is provided in the through holes, andpositive and negative electrodes of the plurality of light-emittingdiodes are respectively connected to the anode electric wire and thecathode electric wire.
 10. The light-emitting device according to claim5, wherein a light-emitting diode from the plurality of light-emittingdiodes, a protective element, or a combination thereof is furthermounted to the electric wire on the rear surface side of the substrate.11. A method of manufacturing a light-emitting device, comprising thesteps of: preparing at least one substrate having a plurality of throughholes; providing an electric wire on a rear surface side of thesubstrate so that a plurality of portions of the electric wirecommunicates with a front surface side of the substrate at the pluralityof through holes of the substrate; and respectively mounting a pluralityof light-emitting diodes to the respective portions of the electric wirethat communicate with the front surface side of the substrate.
 12. Themethod of manufacturing a light-emitting device according to claim 11,wherein after the mounting step, sealing the plurality of light-emittingdiodes mounted on the electric wire.
 13. The method of manufacturing alight-emitting device according to claim 11, wherein each of theplurality of light-emitting diodes is an LED chip.
 14. The method ofmanufacturing a light-emitting device according to claim 11, wherein theelectric wire comprises an anode electric wire and a cathode electricwire, wherein respective portions of the anode electric wire to whichthe plurality of light-emitting diodes is mounted and respectiveportions of the cathode electric wire to which the plurality oflight-emitting diodes is mounted are bent so as to project to the frontsurface side of the substrate from the rear surface side of thesubstrate through the through holes and then again pass through thethrough holes to return to the rear surface side of the substrate, andwherein the plurality of light-emitting diodes is provided on the frontsurface side of the substrate, and positive and negative electrodes ofthe plurality of light-emitting diodes are respectively connected to theanode electric wire and the cathode electric wire.
 15. The method ofmanufacturing a light-emitting device according to claim 11, wherein theelectric wire comprises a plurality of electric wires, wherein one endof each electric wire and another end of each electric wire pass throughthe through holes from the rear surface side of the substrate andproject to the front surface side of the substrate, and wherein theplurality of light-emitting diodes is provided on the front surface sideof the substrate, and positive and negative electrodes of the pluralityof light-emitting diodes are respectively connected to the one end ofone electric wire among the plurality of electric wires and the anotherend of another electric wire among the plurality of electric wires. 16.The method of manufacturing a light-emitting device according to claim15, further comprising a step of folding the electric wires, which passthrough the through holes from the rear surface side of the substrateand project to the front surface side of the substrate, toward the frontsurface side of the substrate.
 17. The method of manufacturing alight-emitting device according to claim 11, wherein the electric wirecomprises an anode electric wire and a cathode electric wire, whereinthe anode electric wire and the cathode electric wire traverse openingplanes of the through holes on the rear surface side of the substrate,and wherein the plurality of light-emitting diodes is provided in thethrough holes, and positive and negative electrodes of the plurality oflight-emitting diodes are respectively connected to the anode electricwire and the cathode electric wire.
 18. The method of manufacturing alight-emitting device according to claim 11 further comprising a step ofmounting a light-emitting diode from the plurality of light-emittingdiodes, protective element, or a combination thereof to the electricwire on the rear surface side of the substrate.